What do you mean by "keep your chosen tempo in memory? The tempo for the piece is set using Tempo text (added by the Text palette, or by Alt+T). I suspect you are talking about the temporary override to the tempo that you can create using the Play Panel. This override is meant to be temporary only, but it does last until you change it - or until you close the file, since those temporary override settings are not saved.
So I am guessing the problem is that you are trying to use the temporary override to set a permanent tempo, but that is not the correct way to set tempo - it should be done using Tempo text.
Comments
What do you mean by "keep your chosen tempo in memory? The tempo for the piece is set using Tempo text (added by the Text palette, or by Alt+T). I suspect you are talking about the temporary override to the tempo that you can create using the Play Panel. This override is meant to be temporary only, but it does last until you change it - or until you close the file, since those temporary override settings are not saved.
So I am guessing the problem is that you are trying to use the temporary override to set a permanent tempo, but that is not the correct way to set tempo - it should be done using Tempo text.
As there has been no response, I close this.